Rockwell Automation Publication 1715-UM001J-EN-P - December 2020 119
Chapter 4          Digital I/O Operation
The 1715-OB8DE digital output module features are as follows:
• Eight isolated output channels per module
• Fail-safe design and operation
• Suitable for simplex and duplex connections for fault tolerant 
applications
• Duplex series output switches with overload protection for each channel
• Voltage and current monitoring on each channel with reverse current 
protection
• Short circuit and open circuit line fault detection
• Dual redundant field power feed capabilities without the need for 
external diodes
• When fitted in duplex configuration, modules can be replaced online 
without system interruption
Common Features
The table lists several features available on 1715 digital I/O modules.
Determining Input Module 
Compatibility
The 1715 digital input modules interface to sensing devices and detect whether 
they are ON or OFF. The 1715 digital input modules convert DC 
ON/OFF signals from user devices to appropriate logic level for use within the 
1715 Redundant I/O System. Typical input devices include the following:
•Proximity switches
• Limit switches
• Selector switches
• Float switches
• Push button switches
When designing a system by using 1715 digital input modules, you must 
consider these items:
• The voltage necessary for your application
• Whether you need a solid state device
• Current leakage
• If your application uses sinking or sourcing wiring
For more information on digital input modules, see the 1715 Technical 
Specifications, publication 1715-TD001
.
ATTENTION: Maintenance must be performed only by qualified 
personnel, otherwise, personal injury or death, or damage to the system 
can result.
Feature Description
Removal and Insertion Under Power (RIUP)
You can remove and insert modules while power is 
applied.
Module level fault reporting and field-side diagnostic 
detection
Fault and diagnostic detection capabilities that 
provide you the information necessary to most 
effectively and efficiently use your module and 
troubleshoot your application.